Method and apparatus for spinning a fiber band

ABSTRACT

A spinning apparatus comprises a spinning chamber, a centrally arranged thread drawoff tube for drawing off thread from the spinning chamber, the thread drawoff tube opening having a radial outer smooth face extending into the path of the thread and an interior annular face which is rough or notched.

Q Unlted States Patent 11 1 3,640,061 Landwehrkamp 1 Feb. 8, 1972 [54]METHOD AND APPARATUS FOR R f nces Cit d SPINNING A FIBER BAND UNITEDATES PATENTS 3,210,923 10/1965 Schlosser ..57/58.95 m] Invent IngdstadtGer 3,367,099 2/1968 Kubovy et a1 57/58.89 y 3,411,283 11/1968 lsomura..57/58.89 [73] Assignee: Schubert 8; Salzer Maschinenfabrik Ak-3,447,298 6/1969 Collins ..57/58.89 tiengesellschaft, Ingolstadt,Germany 3,455,095 7/1969 Makeham et a1 57/58.89 X 3,481,128 12/1969Landwehrkamp et al... .....57/58.89 I 1 Flled= Oct 20,1969 3,481,12912/1969 Shepherd et a1... .,...57/58.89 I21 I App No 867 607 3,520,1227/1970 Shepherd ..57/58.89

Primary Examiner'Dona1d E. Watkins 311| Foreign Application Pr1orityData AtwmeyR9bert Beach Oct. 30, 1968 Germany ..P 18 06 054.3 57ABSTRACT A spinning apparatus comprises a spinning chamber, a cenfi 'itrally arranged thread drawoff tube for drawing off thread l 89 5 95from the spinning chamber, the thread drawoff tube opening [58] FieldofSearch ..57/58. 8. having a radialouter Smooth face extending into thepath of 57/156 the thread and an interior annular face which is rough ornotched.

3 Claims, 3 Drawing Figures E f j 24 2 PATENTED FEB 81972 fmww METHODAND APPARATUS FOR SPINNING A FIBER BAND PRIOR ART The present inventionrelates to methods for the spinning of a fiber band or sliver and moreparticularly to such methods making use of a rotating spinning chamberfrom which the spun thread or yarn is drawn through a centrally arrangeddrawoff tube. The invention also relates to an apparatus for carryingout the method.

In the case of fiber band spinning devices using a rotating spinningchamber it is known that the false twisting of the end of the thread inthe spinning chamber has a substantial infiuence on thread formation andthe quality of the thread. This false twist and the associated movementof twist along the thread from the piece of thread in the thread outlettube to the fiber-collecting surface can be influenced in variousmanners, for instance by stationary or rotating thread outlet tubes(German Pat. No. 489,538), funnels (French Pat. No. 1,419,233)

or bodies of rotation (English Pat. No. 477,259 and German Pat. No.1,178,336). The U.S. Pat. No. 3,210,923 describes the provision of theoutlet edge, over which the thread is drawn from the spinning chamber,with radial grooves or notches in order to improve transmission of thetwist along the thread.

It has, however, been found that the thread binding-in point in the caseof this apparatus has the tendency to change over from the originaldirection of rotation in the direction of the rotation of the spinningchamber into an opposite rotary movement. As a consequence an extremelyweak yarn or thread is produced which often breaks.

As tests have shown, this tendency is less if instead of a notchedoutlet edge of the thread outlet tube use is made of an opening with .asmooth surface. However, in this case the transmission of twist isworse, so that the thread drawoff speed must be reduced.

SUMMARY OF THE INVENTION One object of the present invention istherefore to provide an apparatus with whose aid a drawn-off thread isgiven a considerable degree of false twist and the drawoff speed canthus be increased without the simultaneous occurrence of spinningdifiiculties such as breaks in the thread.

In accordance with the invention the thread for this purpose on itstravel from the thread binding-in point on the collecting surface intothe thread or yarn drawoff tube is first passed over a smooth face andthen over a frictional face and is caused to abut against these facesmaking use of the thread tension.

For carrying out this method the thread or yarn drawoff opening inaccordance with the invention has a smooth outer radial face projectinginto the path of the thread and a rough or notched inner annularsurface.

Although the U.S. Pat. No.3,2l0,923 describes a thread drawofi' tubeopening provided with internal grooves or ribs while having a smoothouter surface, this smooth radial face does not extend into the path ofthe thread but only serves for closing the spinning chamber, that is tosay as a separating means, in order to hold the fed-in fibers free ofthe thread formed. Thus, in the case of this arrangement as well, thedisadvantages of known thread or yarn drawoff tube openings cannot beavoided.

With the construction of the thread drawoff tube opening in accordancewith the invention the drawn off thread or yarn is given, on the onehand, a sufficient false twist by the rough or notched inner annularsurface, but, on the other hand, the smooth outer radial surfaceextending into the path of the thread damps oscillations in the threadso that spinning difficulties as known to occur in the prior art threaddraw ofi tube openings are effectively prevented.

BRIEF DESCRIPTION OF THE VIEW OF THE DRAWING Further details of thefiber band spinning device in accordance with the invention are nowdescribed in more detail with reference to the accompanying drawings.

FIG. 1 shows a spinning apparatus in longitudinal section with thethread or yarn outlet opening tube in accordance with the invention.

FIGS. 2 and 3 show further embodiments of the yarn outlet tube openingin longitudinal section.

DETAILED DESCRIPTION In the fiber band or sliver device with a rotatingspinning chamber 2 and a housing 1, with a lid 11, surrounding thespinning chamber, the fiber material is usually supplied as a fiber bandS through a supply device 5 shown in the drawing in the form of supplyrollers and a fiber band supply tube 51 to the collecting surface 24,from which the fiber band is drawn off as yarn or thread F by acentrally arranged yarn drawoff part, for example a funnel serving as aseparating means, or a yam drawoff tube 6, use being made of a drawofi'device 3.

In the previously known methods the thread or yarn on its path from thecollecting surface 24 to the thread drawoff tube was only passed over asingle face, on which it was caused to abut making use of the threadtension.

It has been found that such a surface, when constructed as a frictionalsurface, brings about a frequent reversal in the direction of rotationof the thread binding-in point E. If, however, this surface is smooth,the movement of twist along the thread is worse so that the threaddrawoff speed must be reduced.

As has been shown by tests, these spinning difficulties can be avoidedby causing the thread to pass during its movement firstly over a smoothface and then over a frictional face, the thread being caused to abutagainstthese faces by making use of the thread tension.

The thread drawoff tube opening end 60 therefore has, in accordance withthe invention, a smooth outer radial face 600, which extends in themanner of a funnel into the tube axial passage 63, and a notchedinterior peripheral face 601 (FIG. 1). The smooth outer radial faceprojects into the path of the yarn moving from the collecting surface 24into the passage 63 so that the yarn is caused to be pressed against thefaces 600 and 601 by its tension. 1

In this manner the thread has a false twist applied to it by the notchedsurface 601. The smooth radial face 600, however, series to damp threadoscillations caused by contact of the thread with the notched face, sothat the oscillations cannot have any objectionable effect on theoperation of the collecting face 24.

If the thread drawofi' tube 6 is made so that it can be displacedaxially, for example by loosening a holding screw 602, differentpositions can be selected in order for the tube end surface 600 toprovide a greater or lesser damping effect in accordance with thespinning conditions it is desired to achieve, the damping being changedby an alteration in the thread deflection angle on the smooth surface600. For this purpose it is possible to provide two relativelyadjustable thread drawoff tubes which telescope one inside the other, asis described in U.S. Pat. No, 3,48l,l28.

The surface 601 can be made in various forms. It is only essential thatit exerts a substantial friction on the thread F. Thus, for example, inaccordance with FIG. 2, an insert 690 is provided, instead of thenotches, whose interior bore conveniently widens towards the interior ofthe spinning chamber 2. The same effect can also be obtained byproviding different coating materials on the two surfaces 600 and 601 orby difference in roughness of the same material.

The opening of the thread or yarn drawoff tube in accordance with theinvention can also be constructed in various different manners. The tubeopening end 60 shown in FIG. 2 has a cylindrical bore 632 adjacent tothe tube axial bore 63 which bases are connected by a rough annularsurface 601 at the end of the tube axial base adjacent to the interiorof the spinning chamber. The enlarged cylindrical bore portion632 of thetube axial bore 63 has a broad radial end face 600 like a plate.

For the invention it is of little importance whether the thread drawofi'tube 6 is arranged in the cover 11 or in the hollow shaft 21 of thespinning chamber 2. It is also possible, instead of the stationarythread outlet tube 6 shown, to use a rotary one, which rotates insynchronism with the rotation of the spinning chamber 2 or independentlyof it.

The combination in accordance with the invention of a smooth contactface 600 with a contact face 601 having a relatively high coefficient offriction achieves a sutficient false twist for obtaining high drawoffspeeds while avoiding the change in the direction of rotation of thethread binding-in point B and associated faults in the quality of theyarn together with a large number of yarn breakages.

What I claim is:

1. In spinning a fiber band using a rotating spinning chamber from whichthe spun thread is drawn off from a thread binding-in point on arotating collecting surface of the spinning chamber into and through acentrally arranged thread drawofi' tube, the method of twisting thethread by tensioning and drawing the thread over a frictional face,wherein the improvement comprises the steps of drawing the tensionedthread over a smooth face between the thread binding-in point of thespinning chamber and the frictional face, and during such drawing of thethread over such smooth face tensioning the thread for pressing itagainst such smooth face.

2. In a spinning apparatus including a spinning chamber having abinding-in point and a single centrally arranged thread drawoff tube fordrawing off thread from the spinning chamber having an inner endprojecting into the spinning chamber, the improvement comprising thedrawoff tube having a mouth flared toward the spinning chamber includingan interior peripheral surface which is rough and a smooth peripheralface at the side of the rough peripheral surface toward the end of thedrawofi tube, of greater circumferential extent than the circumferentialextent of the rough peripheral surface and located inwardly from aconical reference shape joining the rough peripheral surface and thebinding-in point of the spinnning chamber, whereby a thread in passingfrom the binding-in point of the spinning chamber to said roughperipheral surface will be drawn over and pressed against said smoothface.

3. In the spinning apparatus defined in claim 2, the thread drawoff tubeinterior peripheral surface being roughened by being notched.

1. In spinning a fiber band using a rotating spinning chamber from whichthe spun thread is drawn off from a thread binding-in point on arotating collecting surface of the spinning chamber into and through acentrally arranged thread drawoff tube, the method of twisting thethread by tensioning and drawing the thread over a frictional face,wherein the improvement comprises the steps of drawing the tensionedthread over a smooth face between the thread binding-in point of thespinning chamber and the frictional face, and during such drawing of thethread over such smooth face tensioning the thread for pressing itagainst such smooth face.
 2. In a spinning apparatus including aspinning chamber having a binding-in point and a single centrallyarranged thread drawoff tube for drawing off thread from the spinningchamber having an inner end projecting into the spinning chamber, theimprovement comprising the drawoff tube having a mouth flared toward thespinning chamber including an interior peripheral surface which is roughand a smooth peripheral face at the side of the rough peripheral surfacetoward the end of the drawoff tube, of greater circumferential extentthan the circumferential extent of the rough peripheral surface andlocated inwardly from a conical reference shape joining the roughperipheral surface and the binding-in point of the spinnning chamber,whereby a thread in passing from the binding-in point of the spinningchamber to said rough peripheral surface will be drawn over and pressedagainst said smooth face.
 3. In the spinning apparatus defined in claim2, the thread drawoff tube interior peripheral surface being roughenedby being notched.